You can get there either Russian or Latvian citizenship. You can't have both passports. But if you get a Russian citizenship,than you have to make somehow a Latvian visa (that is almost impossible now) or a one-year residence permit (if you have close Latvian origins/you married a Latvian or you invested a huge amount of money there - that was much easier before the war as well, plus now if you want to acquire/prolongate your one-year permit you have to speak Latvian at some level and pay around 1000 eur every year). Basically, in post-Soviet countries you can't have a double citizenship (but in most post-Soviet countries you can have,for example,1 citizenship of the post-Soviet country + another citizenship of the country that was never a part of the USSR). Like I said before: you can't have both Russian and Latvian passports,but ,as an example,you can have both Russian and Polish passports (because Poland wasn't in the USSR).